Variable-leverage driving-crank.



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` VARIABLE LEVEBAGE nmvlns cnANK.

(Application filed Jan. 5,1901.) v 2 Sheets-Sheet I.

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w. S. WEATHERWAX. VARIABLE LEVERAGE DRIVING CBANK.

(Application med Jan. 5, '190m v n (No Model.) I I f2 Sheets-Sheet 2.

II IIIIIIIIIIIIIIIIIII' UNITED .STATES ,M i w."

Panni rricn.

ASSIGNOR OF ONE-I-IALF TO J. P. BYRON, OF

OF NEW MEXICO.

DEMING, TERRITORY VARIABLE-LEVERAGE DRIVING-CRANK.

SPECIFIGATION forming part of Letters Patent No. 687,801, dated December 3, 1901. Application :filed January 5, 1901. Serial No. 42,225. (No model.)

To. LZZ whom it may concern.

` Be it known that I, WALTER S. WEATHER- WAX, a citizen of the United States, residing at Deming, inthe county of Grant and Territory of New Mexico, have inventednew and useful Improvements in Variable-Leverage Driving-Cranks, of which the following is a specification.

This invention relates to new and useful improvements in variable-leverage drivingcrankmechanism especially adapted for use upon bicycles and other velocipedes and motors of various forms, such as steam and gasolene engines, electric motors, duc. and its primary object is to provide acrank which is adapted to receive power and transmit the same to a shaft with which it is connected, the leverage of said crank upon the shaft being varied automatically during the operation of the mechanism. Y

A further object is to employ means whereby wear upon the parts of the device may be readily taken up or compensated for, and means are also employed for reducing friction to the minimum.

With these and other objects in View the invention consists in providing a guide at one end of a shaft and employing a lever which vis slidably mounted within the guide and pivoted to a ring adapted to revolve eccentrically of the shaft. Means of novel construction are employed upon which the ring is mounted, these means being so arranged as to permit the wear upon the ring, rbc., te be readily taken up.

The invention also consists in the novel construction and combination of parts hereinafter more Vfully described and claimed, and illustrated in the accompanying drawings, showing the preferred form of my invention, and in which* Figure l is an elevation of the mechanism, showing the crank in section. Fig. 2 is an enlarged section on line 2 2 of Fig. 1. Fig. 3 is an enlarged elevation of the guide` upon the shaft and showing the lever in position therein. Fig. 4 is a section on line 44 of Fig. 3. Fig. 5 is an elevation of the basen plate of the driving mechanism, showing said plate partly broken away. Fig. 6 is an elevation of a modified form of driving mechanism. Fig. 7 is an enlarged section online 7 7 of Fig. 6. Fig. 8 is a section on line 8 8 of Fig. 9. Fig. 9 is a section on line 9 9 of Fig. 8, and Fig. 10 is a section on line l0 10 of Fig. 1.

Referring to the figures by numerals of reference, 1 is the base of the driving mechan-- ism and is preferably formed in a single piece comprising a rim 2 and spokes 3, connected at their inner ends. The spokes and rim are provided at regular intervals with threaded apertures 1, the apertures within the rim be; ing adapted to receive means, as screws, whereby the driving mechanism may be secured to any suitable structure. The apertures Within the spokes are adapted to receive screws 5, which extend into slots 6,. formed within strips 7, extending longitudinally of the spokes. The inner ends of these strips are beveled, as shown at S, and are adapted to be contacted by a cone 9, whichk engages threads upon a bolt 10, secured at the center of the base 1. This cone is preferably provided with recesses 1l inits outer face, whereby a suitable tool may be placed into engagement therewith, so that the same may be i screwed down upon the beveled ends 8 of strips 7, and thereby slide said strips outward from each other. A nut 12 is preferably mounted upon the bolt 10 and bears upon cone 9, so as to lock the same in position thereon. l

The outer end of each strip 7 is forked, as at 13, the ends of the forkbeingslotted at 14 to receive trunnions 15, extending laterally from a roller 16, which lies within the fork 13 and projects therefrom into a groove 17, formed in the inner or concave face of aring 18. Y It will be understood that each roller 16 projects into the groove 17, and it will thus be seen that the ring 18 is free to revolve upon said rollers and that all wear may bev readily taken up by screwing the cone 9 downward.

ring 18 and is provided at one end with a plate 20, which is secured thereto in any suitable manner and is preferably substantially rectangular in form. At two diagonally oppo- The shaft 19 is arranged eccentrically of the site corners of this plate are secured rollers 21, which are revoluble upon stud-shafts 22, secured to the plate. The remaining corners of the plate are slotted, as at 23, to receive stud-shafts 24, upon each of which is journaled a roller 25, which is preferably smaller than either of the rollers 21,before referred to.

Nuts 26 are mounted upon the stud-shafts 24, so that thesame may be readily locked in adjusted position within the slots 23, and it will thus be seen that the rollers may be adjusted from or toward each other, as may be desired.

The rollers 21 and 25 upon the plate 2O projectinto longitudinally-extending grooves 27, which are formed in opposite sides of a lever 28. This lever is pivoted at one end upon a shaft 29, which is secured in any suitable manner tothe revoluble ring 18, before referred to. A cone 30 and a nut 31 are mounted upon this shaft, so that wear upon the lever 28 may be readily taken up, and a crank 32 extends from the shaft 29 and is adapted to receive the power which is transmitted to the shaft 19. The point of connection between the lever 28 and the ring 18 is preferably partly inclosed by a fiange or guard 33.

Itis thought that from the foregoing description the operation of the device will be readily understood. When the crank 32 is moved in the direction of the arrow shown in Fig. 1, the distance from said crank to the shaft 19 will increase upon the downward stroke of the crank and will diminish as said crank moves backward and upward. Motion will be imparted from the crank to the shaft 19 through the lever 28, which will slide back and forth between the rollers 21 and 25. The rollers 21 are preferably larger than the rollers 25, as they receive all of the pressure from the lever 28, the rollers 25 merely being employed for taking up the wear on rollers 21 and the lever 28.

In Figs. G,7,8, and 9I have shown a modified form of mechanism which may be employed in lieu. of that heretofore described. By referring to said figures it will be seen that a disk 34 is employed in lieu of the base 1, heretofore referred to, and this disk is provided with an annular flange 35, having a bead 36 extending along the outer face thereof. This bead is adapted to extend into a groove 37, formed within the inner concave face of a ring 38, which is preferably formed of two semicircular sections having ears 39 at their ends, which are adapted to be secured together in any desired manner, as by means of bolts 40.

The shaft 19 is provided with a plate 4lat one end thereof, which is employed in lieu of the plate 20, before described, and a groove 42 is formed in the outer face of this plate and is adapted to receive the lever 28. The grooves within this lever instead of receiving rollers 21 and 25, as in the preferred form esvgsoi of my invention, receive flanges 43, which extend inwardly from the walls of the groove 42. By providing mechanism of this construction the rollers and their stud-shafts are dispensed with and the number of parts is thereby materially reduced.

In the foregoing description I have shown the preferred form of my invention; but I do not limit myself thereto, as I am aware that modifications may be made therein without departing from the spirit or sacrificing any of the advantages thereof, and I therefore reserve the right to make all such changes as fairly fall within the scope of my invention.

Having thus fuliy described my invention, what I claim as new, and desire to secure by Letters Patent, is-- 1. The combination with a shaft; of a guide revoluble therewith, a base-plate, arms secured upon said plate, rollers at the ends thereof,a revol uble ring eccentric to the shaft and mounted upon the rollers, a lever pivoted to the ring and slidably mounted within the guide, and means at the inner ends of said arms for adjusting the same longitudinally.

2. The combination with a shaft; of a guide revoluble therewith, a base-plate, strips slidably mounted upon the plate, a roller at one end of each strip, beveled inner ends to said strips, an adjustable cone adapted to contact with said beveled ends whereby the strips may be slid outward, a revoluble ring eccentric to the shaft and mounted upon the rollers, and a lever pivoted to said ring and slidably mounted within the guide.

3. The combination with a shaft having a guide at one end thereof; of a base-plate,

'strips adj ustably secured thereto, rollersjournaled within the outer ends of said strips, beveled inner ends to the strips, an adjustable cone adapted to bear upon the beveled ends whereby the strips may be moved outward, a revoluble ring eccentric to the shaft and having a groove within the concave face thereof adapted to receive the rollers, and a lever pivoted to the ring and slidably mounted within the guide.

4. The combination with a revoluble ring, of a base-plate, strips adjustably secured thereto, means at the inner ends of said strips for adjusting them longitudinally, a shaft eccentric to said ring; a plate secured to one end thereof, diagonally opposite rollers journaled upon the plate, diagonally opposite adjustable rollers journaled upon said plate, and a lever pivoted to the ring and having grooves in the opposite edges thereof adapted to receive the rollers, said lever being slidably mounted therebetween.

In testimony whereof I affix my signature in presence of two witnesses.

WALTER S. WEATHERVAX.

Witnesses:

HUGH M. STERLING, FRANK O. MCCLEARY.

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